[MOBY-dev] lease versus agent for registry updating

[Mark Wilkinson]

Hi all!

Eddie and I are spending the day working on MOBY Central architecture
issues.  We've run into a question that has so many pros and cons that
we decided to toss it out to the list for other opinions.

Keeping MOBY Central up-to-date:

Method 1:  Agent

An agent retrieves the list of SignatureURL's from the registry, and
crawls around retrieving the RDF from each of those URLs.  The RDF is
compared to what is in the registry, and updates/deletions are made.

Consequence to service provider: a service providers machine goes down,
the service is deregistered (the agent can't retrieve the URL) and the
service provider must then actively re-register their services


Method 2:  Lease

Services have a time-stamp in the registry and expire after X time.
They must then be actively re-registered.

Consequence to service provider:  Service providers must set up a cron
(or whatever) that is aware of all of their *current* Signature URL's
and can call MOBY Central to re-register their services on a regular
basis.


Both solutions seem to put an unwanted burden on the service providers,
but the burdens are different in nature and frequency.

Which of these seems preferable?  Are there solutions we haven't thought
of?

???

Mark & Eddie


-- 
"Ontologists do it with the edges!"

Mark Wilkinson
Asst. Professor
Dept. of Medical Genetics
University of British Columbia
PI in Bioinformatics
iCAPTURE Centre
St. Paul's Hospital
Rm. 166, 1081 Burrard St.
Vancouver, BC, V6Z 1Y6
tel: 604 682 2344 x62129
fax: 604 806 9274